In this video I'll be demonstrating what certain nonharmonic frequencies sound like. Nonharmonic frequencies are not common in most western music. But they do occur frequently in other types of music worldwide. In fact, in some types of music like Indonesian Gamelan music, the pitch content is entirely non harmonic. The instrument I'll be playing in this video known as the mbira, primarily generates harmonic frequencies. However, the lower keys also in instruments can also generate non harmonic frequencies when plucked. In those cases, when a low key is plucked, the resulting fundamental pitch, or low note, is mostly obscured by a non-harmonic frequency that emanates simultaneously and is high and bell like. To see what I mean, contrast two low notes played on two different mbira. The first example generates a very prominent non-harmonic frequency that obscures the low pitch. [SOUND] The second example also generates a non harmonic frequency but the fundamental low pitch is still discernible. [SOUND] This effect may be produced intentionally as a matter of personal preference, perhaps to increase the instrument's tamboral, melodic and harmonic capabilities. Makers often spend hundreds of hours tuning these high frequencies. But there also may be cases where the maker doesn't have the metallurgic skill or access to necessary materials like an ample source of metal to tune an instrument as he or she sees fit. To show how these non-harmonic frequencies can work in a musical context, I'll show you two different version of the song called Kuzonga. The first version you'll hear doesn't contain any overwhelming non-harmonic frequencies. [MUSIC] The second version of Kuzonga contains a non-harmonic substitute. You'll see my left thumb continuously returning to that low note with the prominent bell-like non-harmonic frequency. Here's how it sounds. [MUSIC] For further contrast, listen to two renditions of the same song called, Mukatienda, played on two different instruments. The first rendition is played on an instrument whose non harmonic overtones consistently overpower the fundamental pitches of the low keys. [MUSIC] The second rendition of Mukatienda is on an instrument whose fundamental low pitches are more prominent than its non harmonic overtones. [MUSIC] Note that on the spectrum of harmonic to non harmonic instruments, with piano at the harmonic extreme and Indonesian gemal on percussion at the non harmonic extreme, the mbira falls somewhere in the middle depending on the instrument used. It's important to take these non harmonic frequencies in to account when analyzing scales or harmonic preferences among different musical cultures. The presence of these frequencies can confound the result of studies that measure certain physical parameters of sound and/or depend on clear pitch perception.